Composites of beryllium-aluminumcopper



March 12, 1968 Filed May 26, 1967 TEMPERATURE,C

JFIE

E. LARSEN ETAL 3,373,004

COMPOSITES OF' BERYLLIUM-ALUMINUM-COPPER 2 Sheecs-Sheet 2 ALUMINUM- COPPER PHASE DIAGRAM WEIGHT PER CENT ALUMINUM 5 IO [5 6070 80 90 IIO0 ATOMIC PER CENT ALUMINUM IN VENTORS RICHARD H. KROCK EARL I. LARSEN CLINTFORD R. JONES ATTORNEY United States Patent Ofifice 3,373,004 Patented Mar. 12, 1968 3,373,004' COMPOSI'IES F BERYLLIUM-ALUMINUM- COPPER Earl I. Larsen, Indianapolis, Ind., and Richard H. Krock,

Peabody, and Clintford R. Jones, Arlington, Mass, assignors to P. R. Mallory & Co., Ine., Indianapolis, Ind., a corporation of Delaware Filed May 26, 1967, Sex. No. 641,622 4 Claims. (Cl. 29-182.2)

ABSTRAC'I' OF THE DISCLOSURE A composite material whose microstructure consists of beryllium dispersed in an aluminum-copper-silicon-beryllium solid solution alloy matrix was produced by liquid phase sintering pressed powder mixtures of beryllium, aluminum, copper and silicon or powder mixtures of beryllium and pre-alloyed aluminum-copper-silicon.

The present invention relates to ducticle composites of beryllium-alumnum-copper-silicon which can be sintered to substantially theoretical density and to means and methods for providing said composites through liquid phase sintering.

Liquid phase sintering dilfers from the several other types of sintering techniques in that the sintering of the compact is carried out in the presence of a liquid phase. Liquid phase sintering encompasses raising the temperature of the compressed powder metal constituents of beryllium, aluminum, copper and silico1i to a temperature Wherein a predetermined amount of the liquid phase appears. In the liquid phase, one of the metal constituents, the solid, is progressively dissolved in the other metal consttuent or constituents, the lquid. However, the quantities of these constituents are such that, at equilibrium, some solid phase always exists. It is thought that the liquid Wets the solid so as to bring about favorable surface energies existing between the liquid and the solid thereby permitting solution into the liquid phase.

However, heretofore, When beryllium-aluminum-copper-silicon composites were fabricated in accordance With known liquid phase sintering techniques, it was found that the solid beryllium expelled the liquid aluminumcopper-silicon-beryllium alloy from the compact dunng liqid phase sintering. It is thought that the unfavorable surface energy equilibrium causing expulsion of the liquid aluminum-copper-silicon-beryllium alloy is due to a tough, tenacious film of beryllium oxide which is present on each particle of beryllium. The present invention prevents the expulsion of the liquid aluminum-copper-silicon-beryllium alloy from the specimen by using an agency to intervene in the sintering state. The agency either breaks down the oxide film on the beryllium or segregates to the metal oxide interface and lowers the surface energy of the liquid metal With respect to the beryllium oxide film so that the liquid metal progressively dissolves the solid metal.

The agency can be called a fluxing agent or flux, however, the agent has other characteristics which assist in wetting beryllium so as to surround the beryllium With The lack of ductility of beryllium is attributed to the crystal structure of beryllium which is hexagonal close packed. During deformation, the basal planes of the hexagonal close packed structure, being the easiest to slip, are aligned along the Working direction. Since slip is crystallographically diflcult perpendicular to the basal plane, the ductility of beryllium perpendicular to the primary fabrication direction is practically noncxistent.

Several possible solutions have been advanced in an attempt to make beryllium metal sufficently ductile so as to permit a widespread commerci-al acceptance of beryllium. Cross-rolling and cross-forging have been suggested as fabrication methods which might enhance the ductility of beryllium. These fabrication techniques reduced the number of basal planes along the direction of rolling and resulted in improved ductility. However, the degree of improvement was far from satisfactory. The fact remained that beryllium must be classified as brittle at room temperature even utilizing the aforementioned method When ductility perpendicular to the fabrication temperature is considered. In addition, the above-mentioned technique would not be feasible where the fabrication is, by nature, solely along one axis such as swaging, drawing and extrusion.

In recent years, attention has been directed to the fabrcation of beryllium alloys not having the inherent brittleness of beryllium itself but possessing various outstanding properties of the metal such as, for example, low density combined with high strength. It is thought that U.S. Patent 3,082,521 fabricated the first ductile beryllium alloy by rapidly cooling the part from a temperature at which it was liquid. However, the beryllium content of the alloy was not in excess of 86.3 atomic percent which is approximately 33 weight percent of the alloy. Although the beryllium alloy was ductile, the density of the alloy was in eXcess of that of aluminum and about equal to that of titanium.

It has also been suggested that beryllium alloys might be fabricated by pressing and sintering a mix of metal powders. However, such a method results in expulsion of the matrix metal or metals from the beryllium specimen and the eventual freezing of the matrix metal or metals into globs on thesurface of the solid specimen. It is thought that the expulsion of the matrix metal or metals is due to the surface energies of the solid beryllium and the various liquicls formed. The unfavorable surface energy equilibrium is believed to be due to a tough, tenacious film of beryllium oxide which is present on each particle of beryllium.

A means and method have been discovered for preparing a composite of beryllium, aluminum, copper, and silicon containing about 50 to percent, by weight, of beryllium, about 13.4 to about 46.5 percent, by weight, aluminum, about 0.6 to about 3.5 percent, by weight, copper and about 0.3 to about 2.5 percent, by weight, silicon producing a composite having a density about the same as or less than that of aluminum, having hgh strength, and having good ductility. The ductility is due to the resulting microstructure of the composite. By surrounding the beryllium particles With a ductile envelope phase, a composite is formed where, under load, the beryllium is so constrained by the ductile phase that it and the ductile phase deform continuously.

The 85 percent, by weight, ber'yllium composite showed a considerable amount of particle contiguity and would represent, it is thought, an upper limit on the percent by weight of beryllium contained by the composite. A decrease in beryllium content below 50 percent would raise, it is thought, the density value of the composite to a value of lttle interest.

Alkali and alkaline earth halogenide agents such as lithium fluoride-lithium chloride or the like in a determined ratio are utilized to segregate to the solid interface of the beryllium particle and either break down the film on the particle of beryllium and/or alter the liquidsolid surface energy in the system.

Therefore, it is an object of the present invention to provide a ductile beryllium-aluminum-coppensilicon composite havin g low density and high strength.

A further object of the present invention is to provide a ductile composite of beryllium-aluminum-copper-silicon in which beryllium is the predominate ingredient.

Yet stili another object of the present invention is to provide a means and method of producing a ductle composite of beryllium-aluminum-copper-silicon wherein the microstructure consists of beryllium particles surounded by a ductile envelope phase of an aluminum-copper-silicon-beryllium alloy matrix metal.

Yet another object of the present invention is to provide a ductile composite of beryllum-aluminum-coppersilicon containing about 50 to 85 percent, by weight, beryllium, about 13.4 to 46.5 percent, by Weight, aluminum, about 0.6 to 3.5 percent, by weight, copper, and about 0.3 to 2.5 percent, by Weight, silicon.

Another object of the present nvention is to provide a ductile beryllium-aluminum-copper-silcon composite having a matrix phase that is beat treatable.

Another object of the present inventon is to provide a composite of beryllium-aluminum-copper-silicon that may be sintered to substantially theoretical density.

Another object of the present invention is to provide a ductile composite of beryllium-aluminum-copper-silicon containing about 50 to 85 percent, by vveight, beryllium and the remainder an alloy of alluminum-copper-silicon consisting of about 89.5 to 93 percent, by weight, aluminum, about 4 to 7 percent, by weight, copper and about 2-5 percent, by weight, silicon.

Yet another object of the present invention is to provide a means and method whereby a ductile berylliumaluminum-copper-silicon composite may be successfully fabricated in both a practical and economical manner.

A further object of the present invention is to provicle -an agent which elimnates the expulsion of an alloy of aluminum copper silicon beryllium from a beryllium specimen.

' Stili another object of the present invention is to provide an agent to promote liquid phase sintering of a beryllium-alumnum-copper-silicon mixt-ure.

Still another object of the present invention is to provide alkali and alkaline earth halogenide agents used in the fabrication of a berylliurn-aluminum-copper-silicon composite.

A further object of the present invention is to provide a lithium fluoride-lithiuntr chloride agent tor promoting liquid phase sintering in a beryllium, aluminum, copper and silicon mix.

Yet stili another object of the present invention is to provide a lithim fluoride-lithium chloride agent wherein the constituents are used in a predetermined ratio.

The present nvention, in another of its aspects, relates -to novel features of the instrumentalites of the invention desc'ribed herein for teaching the principal object of the inv'ention and to the novel principles employed in the instrumentalities whether or not these features and princf:iples may be used in the said object and/or in the said eld.

With the aforementioned objects enumerated, other objects Will be apparent to those persons possessing ordinary skll in the art. Other objects Will appear in the following descriptionand appended claims. The invention resides in the nove'l combination of elements and in the means and method of achieving the combination as hereinafter described and more particularly as defined in the appended claims.

' In the draWirigs:

FIGURE 1 is a phase diagram for binary alloys of lumirium -s'ilicon.

FIGURE 2 is a phase diagram for binary alloys of beryllium-aluminum.

FIGURE 3 is a phase diagram minum-copper.

FIGURE 4 is an enlargement of a beryllium specimen illustrating an aluminurn-copper-silicon-beryllium matrix metal expelled from the specimen by the forces of surface energy of solid beryllium and the aluminum-coppersilicon-beryllium liquid.

FIGURE 5 is a photomicrograph showing about 70 percent, by weight, beryllium, about 27.9 percent, by Weight, alumnum, 1.2 percent, by weight, copper, remainder silicon composite illustrating beryllium particles surrounded by a ductile envelope phase of an aluminumcopper-silicon-beryllium alloy.

Generally speaking, the means and method of the present invention relates to a ductile beryllium-aluminumcopper-silicon composite fabricated by liquid phase sintering to substantially theoretical density. The composite -contains about 50-85 percent, by weight, of beryllium, about 13.4 to 46.5 percent, by weight, aluminum, about 0.6 to about 3.5 percent, by weight, copper, and about 0.3 to about 2.5 percent, by weight, silicon.

The method of producing the beryllium-aluminumcopper-silicon composite by liquid phase sintering comprises the steps of mixing predetermined portions -of powder beryllium and a powder alloy of aluminumcopper-silicon or aluminum powder, copper powder and silicon powder with a predetermined portieri of an agent selected from the group consisting of alkali and alkaline earth halogenides. The portions are pressed in a die to form a green compact. The compact is then heated to the sintering temperature of beryllium. At this temperature the agent provides a favorable surface energy equilibrium between the beryllium and the aluminum-copper-silicon alloy so that the alloy progressively dissolves the beryllium at the sintering temperature so as to form an aluminumcopper-silicon-beryllium alloy matrix. Thereafter, the beryllium-aluminum-copper-silicon composite may be beat treated and rapidly quenched so as to.preserve the beat treating temperature structure and the aluminum s supersaturated with copper. Precipitation or ageing may be carried out followed by air cooling to room temperature.

More particularly, the method of the present invention comprises mixing powder beryllium of about 50-85 percent, by weight, with a powder alloy of aluminum-coppersilicon or the elemental powders of aluminum, copper and silicon. An agent of lithium fluoride-lithium chloride is in about 0.5 to 2.0 percent, by weight, of the total metal additions is mixed with the beryllium or with the beryllium and the alloy powder or elemental powder. The preferred ratio of the constituent of the agent is about a one to one ratio by weight. The beryllium, the alloy powder or elementari powder, and the agent are pressed so as to form a green compact. The green compact is heated in a non-oxidizing atmosphere such as argon at a temperature of about 700 C. to about 1100 C, At the aforementioned temperatures, the agent provides a favorable surface energy equilibrim between the beryllium and the alloy so that the aluminum-copper-s'ilicon alloy proressively dissolves the beryllium. The microstructure of the resultant composite consists of beryllium particles surrounded by a ductile envelope phase of an alurninum-copper-silicon-beryllium alloy matrix metal. The alloy is sintered to substantially its theoretical density. The alloy may be specially beat treated and rapidly quenched so that the beat treating temperature structure is preserved and the aluminum is supersaturated with copper-silicon. Precipitation or ageing may be carried out followed by air cooling to room temperature.

In carrying out the present invention, a beryllium base compact is fabricated by any suitable means such as powder metallurgy techniques. A suggestedmethod utilizing this technique is to mix beryllium powder with an agent of equal parts of lithium fluoride-lithium chloride.

for binary alloys of alu- It is seen that the ratio of lithium fluoride to lithium chloride may be varied. The milling is carried out for about 1 hour using ceramic balls. Thereafter, a powder alloy of aluminum-copper-silicon or the elemental powders are ball mill mixed with the beryllium and the agent for an additional hour. The blended and mixed powders are compacted to form a green compact by accepted metallurgical methocls such as by compacting Within the confines of a die in a hydraulic or an automatic press or by placing the powder in a rubber or plastic mold and compacting in a hydrostatic press. The green compact is sintered in a non-oxidizing atmosphere such as argon or the like at a temperature of about 700 C. to about 1100 C. It is seen that the range of the sintering temperatures is below the 1277 C. melting point temperature of the beryllium and is above the melting point temperature of the aluminum-copper-silicon alloy. The aluminum-copper-silicon alloy Will dissolve smaller beryllium particles and will dissolve the surfaces of the larger berylliurn powder particles so as to surround the remaining beryllium particles with a ductile envelope phase of an aiuminum-copper-silicon-beryllium alloy during sintering of the compact, The resultant composite of berylliumaluminum-copper-silicon had a density of about 98.5 percent of theoretical density.

Composites containing about 50 to 85 percent, by Weight, of beryllium and the remainder an alloy of aluminum-copper-silicon were successfully fabricated. The agent prevented the expulsion of the liquid aluminumcopper-silicon-beryllium alloy from the compact by the forces of surface energy, that is, preventecl the formation of very fine roundecl droplets of the aluminum-coppersilicon-beryllium alloy on the surface of the beryllium specimen. FIGURE 4 shows a beryllium specimen baving on the surface thereof an expelled alloy 21 of aluminum-copper-siliconberyllium. Specimens from which the aluminum-copper-silicon-beryllium alloy has been expelled have gross porosity and as a result are weak, brittle, and of little commercial value.

The composition of the agent utilized is about 50 parts, by weight, of lithium fiuoride to about 50 parts, by Weight, of lithium chloride. The agent provides an action, such that, upon heating or sintering of the pressed powder mix to the temperature at which the liquid phase forms, expulsion of the melt from the specimen is eliminated. Furthermore, it was found that solution of the beryllium into the alloy was enhanced by the rounded particles of beryllium in the microstructure.

It was found that the amount by Weight of litbium fluoride-lithium chloride agent should exceed 0.5 percent, by weight, of the total of all metal additions. It would appear that the optimum range of the agent is from about 0.5 percent to about 2.0 percent, by Weight, of the total of all metal additions. It is believed that the quantity of lithium fluoride-lithium chloricie agent required is related to the amount necessary to cover the total beryllium surface area. Hence, the minimum amount of agent needed would be a function of the surface area of the beryllium powder, The utilization of lithium fluoride-lithium chloride agent in other than egual parts was dome, It is thought, however, that an egual pars mixture achieves optimum results.

It was found during sintering that substantially 100 percent of the fluxing agent was lost during sintering. This result would seem to indicate that the flux entered into a chemical reacti-on whereon it decomposed and then volatilized and/or the flux volatilized as lithium fluoridelithium chloride.

By using the methods of the present invention and the lithium fluoride-lithium chloride agent, compacts were fabricated containing up to 85 percent, by weight, of beryllium, the remainder an alloy of aluminum-copaersilicon without the use of pressure during sintering. Using powder beryllium having a particle size of 20 microns or finer and using ceramic balls to blend the powder metals and the agent resulted in a composite having a high density. The good strength and low density characteristics of the beryllium were retained and the resulting beryllium-aluminum-copper-silicon composite possessed good ductility. The composite was sintered to about 93-95 percent of its theoretical density by a single sinter and achived about 98.5 percent of theoretical density by a repress and an intermediate re-liquid phase sinter for about 1 hour.

Thus, by substantially surrounding the beryllium particles with a ductile envelope phase of an aluminum-coppersilicon-beryllium-alloy matrix metal, the beryllium and the matrix metal deform continuously under lo-ad.

An aluminurn-silicon phase diagram is illustrated in FIGURE 1. A beryllium-aluminum phase diagram is illustrated in FIGURE 2. A11 aluminum-copper phase diagram is illustrated in FIGURE 3. Copper and silicon strengthen aluminum by solid solution hardening and precipitation hardening. The theory of the deformation of dispersed particle composite materials states that ductility in such a composite Will be enhanced When the constrained flow stress of the matrix phase can be made as equal as possible to the flow stress of the dispersed particles. Hence, copper and silicon are used to harden aluminum. Once the composite has been cooled to room temperature, the eflectiveness of the copper and the silicon are further brought into play by a subsequent beat treatment. It was found that beat treating the composite at about SUO-550 C. for about 12 hours is suflcient to completely dissolve all the copper and silicon in the aluminum. The composite is rapidly quenched into a satisfactory medium such as water or the like, such that the high temperature structures is preservecl and the aluminum is supersaturated with copper and silicon. Hence, the solutionizing treatment contains all the copper and silicon in solution. The copper and the silicon can be precipitated out of the supersaturated solid solution thereby increasing the strength of the alumniumcopper-silicon matrix. An advantage of the berylliumaluminum-copper-silicon composite is that the matrix phase is beat treatable.

Attention is directed to FIGURE 5, wherein a photomicrograph of about 500 magnifications shows a composite of 30 percent, by weight, aluminum-copper-silicon alloy in beryllium after being etched by any suitable etching means such as a dilute solution of ammonium hydroxide and hyclrogeu peroxide. The areas 10 are beryllium particles. The areas 11 are the aluminum-cooper-silicon-beryllium alloy surrouncling the beryllium particles. 7

It will be recognized by those skilled in the art that minor additions of other metals may be added to the matrix of the composite to improve one or more of the pnysical properties such as machinability, deoxidation, and the like. For example, an addition of a trace to about 1 perccnt, by weight, of either bismuth manganese, or lead to the composite improves machinability thereof. An acidition of a trace to about 1 percent, by weight, of magnesium to the composite Will improve the deoxidation property of the composite.

Exampie l shows the expulsion of the liquid from a beryllium specimen and Examples 2-17 are illustrative of the preparation of beryllium-aluminum-copper-silicon composites by liquid phase sintering.

Example 1 Expulsion of the liquid aluminum-copper-silicon-beryllium alloy from the solid beryllium specimen occurs during liquid phase sintering when the agent of lithium fluoricle-lithium chloride is not used in the preparation of a berylliurn-aluminum-copper-silicon composite.

A mixture of about 70 percent, by weight, of beryllium having a particle size of 200 mesh or finer was ball mill mixed with about 30 percent, by weight, of an alloy of aluminum-copper-silicon or the elmental powders of suitable particle size. The alloy contained about 93 percent,

by weight, aluminum, about 4 percent, by weight, copper and the remainder silicon. The milled mixture Was pressed by any suitable means such as by an automatic press at a suitable pressure to provide a green compact sturdy enough to be handled. It Was found that pressures of from about 15,000 to 20,000 pounds per square inch resulted in a green compact having a density from about 50 to 60 percent of theoretical densty and sufliciently strong to be handled. Sintering of the compact was carried out in an argon atomsphere at about 1100 C. for about 1 hour. This tecbnique, due to the surface energies of the solid beryllium and the liquid formed, resulted in the expulsion of the liquid from the specimen and its eventual freezing into rounded globs on the surface of the specimen as shown in FIGURE 4.

Example 2 A composite of about 70 percent, by weight, beryllium, about 27.9 percent, by Weight, aluminum, about 1.2 percent, by Weight, copper and the remainder silicon.

A mixture of about 70 percent, by weight, oi beryllium powder having a particle size of 200 mesh or finer Was hall mill mixed using ceramic balls With about 30 percent, by Weight, of an alloy of aluminum-copper-silicon powder of suitable particle size. The alloy contained about 93 percent, by weight, aluminum, about 4 percent, by Weight, copper, and the remainder silicon. Also ball mill mixed With the beryllium and alloy powders was about 1.0 percent, by Weight of the total metal additions equal parts of an agent of lithium fluoride-lithium chloride. Mixtures of the beryllium and alloy powders were also prepared With the agent having 0.5 and 2.0 percent, by weight, of the total metal additions using varying ratios of lithium fluoride-lithium chloride. The milled mixture Was pressed by any suitable means such as by an automatic press at a suitable pressure to provide a green compact sturdy enough to be handled. It was foun-d that pressures of from about 15,000 to 20,000 pounds per square inch resulted in a green compact having a density of from 50 to 60 percent of: theoretical density and sufliciently strong to be harrdled. Sintering of the compact was carried out in an argon atmosphere at about 1100 C. for about 1 hour. A second press followed by a second sinter at about 1100 C. for about 1 hour raised the density of the composite to about 98 percent of theoretical density. The composite was heat treated at about 550 C. for about 1 hour so as to completely dissolve all the copper and the silicon into the aluminum. The composite was then rpidly quenched so that the heat treating temperature structure Was preserved and the aluminum was supersaturated with copper and silicon. The copper and the silicon preciptated from the supersaturated solid solution thereby precipitation hardenng the composite by heating the composite to about 160 C. for about 3 to 5 hours.

Exam:ple 3 A composite of about 70 percent, by wegbt, beryllium, about 27.9 percent, by weight, aluminum, about 1.2 percent, by weight, copper and the remainder silicon.

A -mixture of beryllium powder having a particle size of 20 micron or finer Was hall mill mixed With about 2.0 percent, by weight, of the total metal additions equal parts of an ageut of lithium fluoride-lithium chloride. The milling was carried out Wit-h ceramic balls for about 1 hour. Thereafter, an alloy powder of about 93 percent, by weight, aluminum, about 4 percent, by Weight, copper and 3 percent, by Weight, silicon Was hall mill mixed With the beryllium for about 1 hour. Ceramic balls were used to mix the powders. The beryllium constituted about 70 percent, by Weight of the blended powders and the alloy powder constituted about 30 percent of the blended powders. Mixtures of the beryllium and alloy powders were also prepared With the agent having 0.5 and 1.0 percent, by weight, of the total metal additions using varying ratios of lithium chloride to lithium fluoride. The

milled mixture was pressed by any suitable means such as by an automatic press at a suitable pressure to provide a green compact sturdy enough to be handled. It was found that pressures o from about 15,000 to 20,000 pounds per square inch resulted in a green compact baving a density of from about 50 to 60 percent of theoretical densty and sufliciently strong to be handled. Sintering of the compact Was carried out in an argon atmosphere at about 800 C. for about 1 hour. A composite was yielded having a density of about 99% of theoretical density. Another composite was prepared using the above procedure but sintering for /2 hour. Both composites were repressed and resintered. Each composite was beat treated at about 500 C. for about 1 hour so as to dissolve the copper and the silicon into the aluminum. Each composite was then rapidly quenched so that the beat treating temperature structure was preserved and the aluminum Was supersaturated With copper and silicon. It was found that the composite sintered for 1 hour had a density of about 98.5 percent of theoretical density and the composite sintered for about /2 hour had a density substarrtially the same. A sintering temperature as low as 700 C. may be used but it is preferred that a sintering temperature of 800 C. or above be used.

Example 4 A composite of about 70 percent, by weght, beryllium, 27.9 percent, by weight, aluminum, about 1.2 percent, by weight, copper, and the remainder silicon.

The procedure of Example 3 was followed using about 70 percent, by weight, beryllium, about 27.9 percent, by weight, aluminum powder, about 1.2 per-cent, copper powder, and the remander silicon powder. Individual composites were prepared using 0.5, 1.0 and 2.0 percent, by weight, of the total metal additions.

Example 5 A composite of about 70 percent, by weight, beryllium, 27.9 percent, by weight, aluminum, 1.2 percent, by weight, copper and the remainder silicon.

The procedure of Example 3 was followed using about 70 percent, by weight, beryllium powder, mixed with about 30 percent, by weight, of an alloy powder of 3.11.111'1- numcopper-silicon. The alloy contained about 93 percent, by weight, aluminum, about 4 percnt, by weight, copper, and the remainder silicon. Individual composites were prepared using 0.5, 1.0 and 2.0 percent by weight of the total metal additions of the agent lithium fluoride-lithium chloride in equal proportions and in unequal proportions at temperatures of about 1100 and 1200 for /2 hour and 1 hour using the aforementioned procedure.

Example 6 A composite of about 50 percent, by weight, beryllium, about 45.5 percent, by weight, aluminum, 2.0 percent, by weight, copper and the remainder silicon.

The procedure of Example 3 was followed using 50 percent, by Weight, beryllium powder, mixed With about 50 percent, by weight, of an alloy powder of aluminumcopper-silicon. The alloy contained about 91 percent, by weight, aluminum, 5 percent, by Weigbt, silicon and the remainder copper. Individual composites were prepared using 0.5, 1.0 and 2.0 percent, by weight, of the total metal additions of the agent lithium fluoride-lithium chloride at temperatures of about 800, 900, 1000 and 1100 C. for /2 hour and for 1 hour using the aforementioned procedure.

Example 7 A composite of about 50 percent, by weight, beryllium, about 46.5 percent, by weight, aluminum, 2.0 percent, by weight, copper and the remainder silicon.

The procedure of Example 3 was followed using 50 percent, by weight, beryllium powder, mixed With about 46.5 percent, by weight, aluminum powder, 2.0 percent,

9 by weight, copper powder and the remainder silicon powder. Individual composites were prepared using 0.5, 1.0 and 2.0 percent by weight of the total metal additions of an agent lithium fluoride-lithium chloride at temperatures of about 800, 900", 1000" and 1100 C. for V2 hour and for 1 hour using the aforementioned procedure.

Example 8 A composite of about 50 percent, by weight, beryllium, about 45.5 percent, by Weight, aluminum, about 2.75 percent, by weight, copper, and the remainder silicon.

The procedure of Example 3 was followed using 50 percent, by weight, beryllium powder, mixed With an alloy of aluminum-cbpper-silicon. The alloy contained about 91 percent, by weight, aluminum, 5.5 percent, by weight, coppe'r, the remainder silicon. Individual composites Were prepared using 0.5, 1.0 and 2.0 percent by weight of the total metal additions of an agent lithium fluoride-lithium chloride at temperatures of about 1100 C. and 1200 C. for /2 arid for 1 hour using the aforementioned procedure.

Example 9 A composite of about 50 percent, by weight, beryllium, about 45.5 percent, by weight, aluminum, about 3.5 percent, by Weight, copper, and the remainder silicon.

The procedure of Example 3 was followed using 50 percent, by weight, beryllium powder, mixed With an alloy of aluminum-copper-silicon. The alloy contained about 91 percent, by Weight, aluminum, 7 percent, by weight, copper, the remainder silicon. Individual composites were prepared using 0.5, 1.0 and 2.0 percent by weight of the total metal additions of an agent lithium -fluoride-lithium chloride at temperatures of about 1100 C. and 1200 C. tor A; hour and for 1 hour using the aforementioned procedure.

Example 10 A composite of about 50 percent, by weight, beryllium, about 44.75 percent, by weight, aluminum, about 3.5 percent, by Weight, copper, and the remainder silicon.

The procedure of Example 3 was followed using 50 percent, by Weight, beryllium, powder, mixed with an alloy of aluminum-copper-silicon. The alloy contained about 89.5 percent, by weight, aluminum, 7 percent, by Weight, copper, the remainder silicon. Iudividual composites were prepared using 0.5, 1.0 and 2.0 percent by weight of the total metal additions of an agent lithium fluoride-lithium chloride at temperatures of about 1100 C. and 1200 C. for /2 hour and for 1 hour using the aforementioned procedure.

Example 11 A composite of about 60 percent, by weight, beryllium, 37.2 percent, by weight, aluminum, 1.6 percent, by weight, copper, and the remainder silicon.

The procedure of Example 3 was followed using 60 percent, by Weight, beryllium powder, mixed with about 40 percent, by weight of an alloy powder of aluminumcopper-silicon. The alloy contained 93 percent, by weight, aluminum, 4 percent, by weight, copper and the remainder silicon. Individual composites were prepared using 0.5, 1.0 and 2.0 percent by Weight of the total metal additions of the agent lithium fluoridelithiurn chloride at temperatures of about 800, 900, 1000 and 1100 C. for /2 hour and for 1 hour using the aforementioned procedure.

Example 12 A composite of about 75 percent, by weight, beryllium, 13.25 percent, by weight, aluminum, 1.0 percent, by Weight, copper, and the remainder silicon.

The procedure of Example 3 was followed using 75 percent, by weight, beryllium powder, mixed With about 25 percent, by weight, of an alloy powder of aluminumcopper-silicon. The alloy contained 93 percent, by weight,

A composite of about percent, by Weight, beryllium, 13.6 percent, by weight, aluminum, 0.6 percent, by Weight, copper, and the remainder silicon.

The procedure of Example 3 was followed using 85 percent, by Weight, beryllium powder, mixed With about 15 percent, by Weight, of an alloy powder of aluminumcopper-silicon. The alloy contained about 91 percent, by weight, aluminum, 5 percent, by weight, silicon, the remainder copper. Individual composites were prepared using 0.5, 1.0 and 2.0 percent by weight of the total metal additions of the agent lithium fluoride-lithium chloride at temperatures of about 800, 900, 1000 and 1100 C. for /2 hour and 1 hour using the aforementioned procedure.

Example 14 A composite of about 85 percent, by weight, beryllium, about 13.9 percent, by Weight, aluminum, about 0.6 percent, by weight, copper, and the remainder silicon.

The procedure of Exarnple 3 was followed using 50 percent, by weight, beryllium powder, mixed With an alloy of aluminum-copper-silicon. The alloy contained about 93 percent, by weight, aluminum, 4 percent, by weight, copper, the remainder silicon. Individual composites were prepared using 0.5, 1.0 and 2.0 percent by weight of the total metal additions of an agent lithium fluoridelithium chloride at temperatures of about 1100 C. and 1200 C. for hour and for 1 hour using the aforementioned procedure.

Example 15 A composite of about 50 percent, by weight, beryllium, about 13.6 percent, by Weight, aluminum, about 0.8 percent, by weight, copper, and the remainder silicon.

The procedure of Example 3 was followed using 50 percent, by weight, beryllium powder, mixed with an alloy of aluminum-copper-silicon. The alloy contained about 91 percent, by weight, aluminum, 5.5 percent, by Weight, copper, the remainder silicon. Individual composites were prepared using 0.5, 1.0 and 2.0 percent by weight of the total metal additions of an agent lithium fluoride-lithium chloride at temperatures of about 1100 C. and 1200 C. for /2 hour and for 1 hour using the aforementioned procedure.

Example 16 A composite of about 50 percent, by weight, beryllium, about 13.7 percent, by weight, aluminum, about 1.0 percent, by weight, copper, and the remainder silicon.

The procedure of Example 3 was followed using 50 percent, by weight, beryllium powder, mixed With an alloy of aluminum-copper-silicon. The alloy contained about 91 percent, by weight, aluminum, 7 percent, by weight, copper, the remainder silicon. Individual composites were prepared using 0.5, 1.0 and 2.0 percent by weight of the total metal additions of an agent lithium fluoride-lithium chloride at temperatures of about 1100 C. and 1200" C. for /2 hour and for 1 hour using the aforementoned procedure.

Example 17 A composite of about 50 percent, by weight, beryllium, about 13.4 percent, by weght, aluminum, about 1.0 percent, by Weight, copper, and the remainder silicon.

The procedure of Example 3 was followed using 50 percent, by weight, beryllium powder, mixed With an alloy of aluminum-copper-silicon. The alloy contained about 89.5 percent, by weight, aluminum, 7 percent, by weght, copper, the remainder silicon. Individual com- 1 1 postes were prepared using 0.5, 1.0 and 2.0 percent by weight of the total metal additions of an agent lithiurn fluorde-lithium chloride at temperatures of about 1100 C. and 1200 C. for hour and for 1 hour using the aforementioned procedure.

The present invention is not intended to be limited to the disclosure herein, and changes and modifications may be made in the disclosure by those skilled in the art without departing from the spirit and scope ci che novel concepts of this invention. Such modifications and variations are consdered to be Within the purview and scope of this invention and the appended claims.

Having thus described our invention, We claim:

1. A ternary metal composite consisting essentally of about 50-85 percent, by weight, of beryllium, and the remainder an alloy of aluminum-copper-silicon.

2. A ternary metal composite according to claim 1, wherein said beryllium particles are surrounded by a matrix of an alloy of aluminum-oopper-silicon-beryllium.

3. A metal composite according to claim 1, wherein said composite consistng essentially of about 46.5 t 13.4 percent, by weight, aluminum, about 0.6 to 3.5 percent, by Weight, copper, and about 0.3 to 2.5 percent, by weight, slicon.

4. A metal composite accoxding to c1aim 1, wherein sad alloy of aluminum-copper-silicon consisting essentially of about 89.5 to 93 percent, by Weight, aluminum, about 4 to 7 percent, by weight, copper, and about 2 to 5 percent, by weight, silicon.

References Cted UNITED STATES PATENTS 2,072,067 2/1937 Donahue -15o 3,322,512 5/1967 Krock 29-1s2.2 3,322,514 5/1967 Krock 29-1s2.2 3,323,880 6/1967 Krock 29 -1s2.2

CARL D. QUARFORTH, Primwry Examiner. A. J. STEINER, Assistant Examiner. 

